1. Field of the Invention
The present invention relates to a fabric belt for a machine for the production of web material, particularly paper or cardboard. Such a fabric belt may be utilized, for example, in a forming section as a forming screen.
2. Description of the Related Art
In the production of web material, such as paper, it is generally required that a very fine structuring is present at the web material contact side, that is to say the side the web material to be produced is in direct contact with, in order to avoid any marking effects. An abrasion or wear volume that is as large as possible should be present on the running side, that is to say on the side that is in contact with various rollers deflecting and advancing the web material, or a very robust construction should be created in order to keep wear and tear at a minimum.
A composite fabric for machine screens is known from EP 0 432 413 A1, wherein two fabric layers on top of each other, having two layers of transverse threads arranged directly on top of each other, are provided. The number of transverse threads of the layer on the paper side corresponds to the number of transverse threads of the layer on the machine or running side. Threads extending in longitudinal direction of the fabric are incorporated into both fabric layers, and alternate on the crossing points between both fabric layers in order to create a structural connection between the same.
WO 2006/020414 A1 discloses a fabric for a paper machine, having two fabric layers positioned on top of each other, including warps and wefts. For this purpose the number of wefts in the fabric layer on the paper side is twice as high as the number of warps in the fabric layer on the running or machine side.
WO 2004/085740 A2 discloses a fabric belt for a paper machine, wherein the connection between two fabric layers is carried out by way of said warps that are structurally incorporated and alternating at crossing points between the fabric layers. The fabric layers further include respective layers of wefts, wherein the number of wefts in the fabric layer on the paper side is in turn twice as large as the number of wefts in the fabric layer on the running side.
A fabric belt for a paper machine is known from EP 1 605 095 A1, wherein both fabric layers are embodied with threads extending in a longitudinal belt direction, wherein the number of said threads in the fabric layer on the running side is twice as large as that in the fabric layer on the paper side. The connection of both fabric layers is carried out by way of said structurally binding threads extending in the longitudinal direction and transverse threads alternating between the fabric layers.
What is needed in the art is a fabric belt for a machine for the production of web material, having a high degree of wear resistance and very low marking properties.